### Please describe the problem.

our datalad tests started to fail recently (in [this PR](https://github.com/datalad/datalad/pull/7372) is the effort to troubleshoot etc).

Here is what we see with recent version using  such simple script:

```
#!/bin/bash

export PS4='> '

set -eu
set -x

cd "$(mktemp -d ${TMPDIR:-/tmp}/dl-XXXXXXX)"

git init
git annex init

n='gl\orious'
# touch "$n"
git annex add --json --json-error-messages "$n"
```

that now 

```
❯ ( source /home/yoh/git-annexes/10.20230407+git63-g3d1d77a1bb.env ; bash escaped.sh )
>> mktemp -d /home/yoh/.tmp/dl-XXXXXXX
> cd /home/yoh/.tmp/dl-OAXQ1CE
> git init
Initialized empty Git repository in /home/yoh/.tmp/dl-OAXQ1CE/.git/
> git annex init
init  ok
(recording state in git...)
> n='gl\orious'
> git annex add --json --json-error-messages 'gl\orious'
git-annex: "gl\\orious" not found
add: 1 failed
```

so we get `\\` instead of `\` in the output printed by git-annex

<details>
<summary>previously was all fine</summary> 

```shell
❯ ( source /home/yoh/git-annexes/10.20230407.env ; bash escaped.sh )
>> mktemp -d /home/yoh/.tmp/dl-XXXXXXX
> cd /home/yoh/.tmp/dl-1TzrWdi
> git init
Initialized empty Git repository in /home/yoh/.tmp/dl-1TzrWdi/.git/
> git annex init
init  ok
(recording state in git...)
> n='gl\orious'
> git annex add --json --json-error-messages 'gl\orious'
git-annex: gl\orious not found
add: 1 failed
```
</details>

[[!meta author=yoh]]
[[!tag projects/datalad]]

> [[closed|done]] --[[Joey]]
